Час ізоволюмічного розслаблення міокарду як параметр оцінки діастоли у котів.

Abstract

у статті приведено оцінку діастолічної функції серця у кішок. Один із параметрів, що характеризує діастолічну функцію серця є час ізоволюмічного розслаблення міокарду (ЧІВР). Включений параметр є показником ранніх змін в міокарді, що може супроводжувати початкові етапи діастолічної дисфункції. Оцінку ЧІВР проводили у свійського кота британської короткошерстнох породи та порівнювали величину цього показника з нормативними значеннаями котів інших порід.

в статья проведена оценка диатолической дисфункции сердца у домашнего кота. Одним из параметров, который характеризирует диастолическую функцию сердца есть время изоволюмического расслабления миокарда (ВИВР). Этот параметр араметр описывает ранние изменения в миокарде, которые могут сопровождать начальные этапы диастолической дисфункции. Оценку ВИВР проводили у домашнего кота британской короткошерстной породы и сравнивали уровень этого паказателя с нормативными значениями для котов других пород.

the article is dedicated to evaluation of diastolic dysfunction in cats. One of the parameter is isovolumetric relaxation time (IVRT). This parameter has shown the earliest changes of diastolic function. We evaluate IVRT in British shorthair cats and compare it with references ranges of other breeds. One of the most common cardiologic disease in domestic cats is hypertrophic cardiomyopathy (HCM). This disease is accompanied by a thickening of the walls of the heart and leads to diastolic disfunction. Despite the fact that the disease occurs quite often, it is difficult to diagnose. In most cases the disease completely asymptomatic. The first sign may be sudden death due to tromboembolism, acute heart failure and pulmonary edema. There are many methods of diagnosis of cardiomyopathy іп domestic cat - electrocardiography, radiography, determination of cardiac troponin, etc . But the most accurate method of diagnosis of cardiomyopathy is echocardiography. This method identify the problem very early, and make prophylaxis more effective. It is believed the reason of heart failure is systolic dysfunction. But the last few decades there is evidence of diastolic dysfunction in medicine. Diagnisis of diastolic dysfunction is difficult because the diastolic changes do not cause symptoms in people or in animals. Materials of and methods: The study was conducted in the veterinary clinic ZOOLUX, Kyiv. During the period from January 2015 to December 2016 EchoCG was conducted on 28 cats. All studies were performed using ultrasound machine of expert class - ESAOTE MyLab 70. 13 animals were excluded from the study. Sensored cats were divided into 2 groups: animals without septal thickening (8 animals) and animals with signs of hypertrophic cardiomyopathy in various stages (7 animals). Results and discussion. Diastole is a complex process that is regulated as internal and external factors. Normally diastole has several phases. The first phase is isovolumetric myocardial relaxation. The second phase is a rapid passive ventricular filling. The third - a slow passive filling and fourth - the phase of active ventricular filling. The most cats with hypertrophic cardiomyopathy, restrictive cardiomyopathy or dilated cardiomyopathy has signs of impaired diastolic function on EchoCG. These changes take place in the period before the onset of clinical signs. Even small changes in diastolic function may indicate early stage of heart diseases. The clinical symptoms, such as dispnoe, decreased activity, congestive heart failure usually occur when change are in 3-4 phase of diastole. Therefore, the class of diastolic dysfunction has prognostic value. According to results of our study IVRT is a good parameter for diastolic evaluation. Prolongation of IVRT is indicator of impaired ability to relaxation and is parameter of early diastolic dysfunction. Reference ranges for IVRT in British shorthaired cats are the same as for other breeds ( 38-45ms).